<?php
/**
 ============================================================
 * Last committed:     $Revision: 127 $
 * Last changed by:    $Author: fire $
 * Last changed date:    $Date: 2013-03-27 09:19:53 +0200 (ñð, 27 ìàðò 2013) $
 * ID:       $Id: datediff.php 127 2013-03-27 07:19:53Z fire $
 ============================================================
 Copyright Angel Zaprianov [2009] [INFOHELP]
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
 http://www.apache.org/licenses/LICENSE-2.0
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 * --------------------------------------
 *       See COPYRIGHT and LICENSE
 * --------------------------------------
 */
    if (!defined('FIRE1_INIT')) { exit("<div style='background-color: #FFAAAA; '> error..1001</div>"); }



/**
* put your comment there...
*
* @param mixed $interval
* @param int $datefrom
* @param int $dateto
* @param mixed $using_timestamps
* @return float
*/
function datediff($interval, $datefrom, $dateto, $using_timestamps = false) {
    /*
    $interval can be:
    yyyy - Number of full years
    q - Number of full quarters
    m - Number of full months
    y - Difference between day numbers
        (eg 1st Jan 2004 is "1", the first day. 2nd Feb 2003 is "33". The datediff is "-32".)
    d - Number of full days
    w - Number of full weekdays
    ww - Number of full weeks
    h - Number of full hours
    n - Number of full minutes
    s - Number of full seconds (default)
    */

    if (!$using_timestamps) {
        $datefrom = strtotime($datefrom, 0);
        $dateto = strtotime($dateto, 0);
    }
    $difference = $dateto - $datefrom; // Difference in seconds

    switch($interval) {

    case 'yyyy': // Number of full years

        $years_difference = floor($difference / 31536000);
        if (mktime(date("H", $datefrom), date("i", $datefrom), date("s", $datefrom), date("n", $datefrom), date("j", $datefrom), date("Y", $datefrom)+$years_difference) > $dateto) {
            $years_difference--;
        }
        if (mktime(date("H", $dateto), date("i", $dateto), date("s", $dateto), date("n", $dateto), date("j", $dateto), date("Y", $dateto)-($years_difference+1)) > $datefrom) {
            $years_difference++;
        }
        $datediff = $years_difference;
        break;

    case "q": // Number of full quarters

        $quarters_difference = floor($difference / 8035200);
        while (mktime(date("H", $datefrom), date("i", $datefrom), date("s", $datefrom), date("n", $datefrom)+($quarters_difference*3), date("j", $dateto), date("Y", $datefrom)) < $dateto) {
            $months_difference++;
        }
        $quarters_difference--;
        $datediff = $quarters_difference;
        break;

    case "m": // Number of full months

        $months_difference = floor($difference / 2678400);
        while (mktime(date("H", $datefrom), date("i", $datefrom), date("s", $datefrom), date("n", $datefrom)+($months_difference), date("j", $dateto), date("Y", $datefrom)) < $dateto) {
            $months_difference++;
        }
        $months_difference--;
        $datediff = $months_difference;
        break;

    case 'y': // Difference between day numbers

        $datediff = date("z", $dateto) - date("z", $datefrom);
        break;

    case "d": // Number of full days

        $datediff = floor($difference / 86400);
        break;

    case "w": // Number of full weekdays

        $days_difference = floor($difference / 86400);
        $weeks_difference = floor($days_difference / 7); // Complete weeks
        $first_day = date("w", $datefrom);
        $days_remainder = floor($days_difference % 7);
        $odd_days = $first_day + $days_remainder; // Do we have a Saturday or Sunday in the remainder?
        if ($odd_days > 7) { // Sunday
            $days_remainder--;
        }
        if ($odd_days > 6) { // Saturday
            $days_remainder--;
        }
        $datediff = ($weeks_difference * 5) + $days_remainder;
        break;

    case "ww": // Number of full weeks

        $datediff = floor($difference / 604800);
        break;

    case "h": // Number of full hours

        $datediff = floor($difference / 3600);
        break;

    case "n": // Number of full minutes

        $datediff = floor($difference / 60);
        break;

    default: // Number of full seconds (default)

        $datediff = $difference;
        break;
    }

    return $datediff;

}
